Before you listen to the audio, heed these directions:

Press play, and be prepared to want to pull your hair out.

The strange loop effect creates what sounds like an infinitely ascending scale.

Such an effect was originally produced by psychologist and musician Diana Deutsch, a pioneer in the field of audio illusions. She accomplished this kind of "pitch circularity" by digitally manipulating the overtones of each individual note in a mathematically precise way.

For a visual representation of a strange loop, take a look at these Penrose steps, aka the impossible staircase.

Like the Penrose staircase, which seems to go up and down in an endlessly circular way, Deutsch creates a musical scale in semitones that repeatedly circles back to the same note.

In the words of Deutsch (for all you music geeks out there): "We repeatedly traverse the pitch class circle in clockwise direction, so that we play C, C#, D, and so on all around the circle, until we reach A, A#, B — and then we proceed to C, C#, D again, and so on."

There are many audio illusions that fall into the category of the "strange loop." The Shepard tone, invented in 1964 by psychologist Roger Shepard, is another example. By using a computer, Shepard was able to create an audible fractal where the tones seem to go up or down forever in pitch, while simultaneously going nowhere at all.